An oxetane compound has recently attracted attention as a monomer capable of photo-initiated cationic polymerization or curing, and various oxetane compound synthesis methods have been proposed along with developments of many monofunctional and polyfunctional oxetane compounds.
As such oxetane compound, an oxetane compound represented by the following formula (4)
(wherein R5 is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atom(s), a fluoroalkyl group having 1 to 6 carbon atom(s), an allyl group, an aryl group, a furyl group, or a thienyl group; R6 is a group selected from a chained or branched poly(alkyleneoxy) group, a xylylene group, a siloxane bond, and an ester bond; Z is an oxygen atom or a sulfur atom; and m is an integer of 2 to 4), is disclosed in a patent document (see Patent document 1).
Further, a biphenyl derivative having an oxetane ring represented by the following formula (5)
(wherein R7 is a hydrogen atom or an alkyl group having 1 to 6 carbon atom(s)), and a biphenyl derivative having an oxetane ring represented by the following formula (6)
(wherein each of R8 to R11 represents a hydrogen atom or a methyl group; and each of R12 and R13 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atom(s)) have been also proposed (see Patent Documents 2 and 3).
The above compounds are generally obtainable by using an alkali metal such as sodium hydroxide and potassium hydroxide as a base and synthesizing oxetane ester sulfonate and a divalent phenol compound corresponding to the oxetane ester sulfonate under the presence of the base. In addition, a phase transfer catalyst such as a quaternary ammonium salt is used according to the necessity in order to increase a yield of the compounds in the synthesis. Further, the oxetane compounds have heretofore been used as a material for coating compositions and adhesives for the purposes of increasing heat resistance, adhesion, and the like, and a use of the oxetane compound as a material for forming an optical waveguide has recently been proposed (see Patent Documents 4 and 5). The optical waveguide is incorporated into an optical waveguide device, an optical integrated circuit, and an optical wiring board and is used widely in the fields of optical communication, optical information processing, and like general optics.
Patent Document 1: JP-A-6-16804
Patent Document 2: JP-A-11-106380
Patent Document 3: JP-A-2001-31665
Patent Document 4: JP-A-2000-356720.
Patent Document 5: JP-A-2003-147045